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在运行程序以从网络摄像头捕获的视频中抓取帧时，我遇到了 NullPointerException 的问题。我试图更改捕获设备的设置，但没有类似的选项

“vfw:Microsoft WDM Image Capture (Win32):0” 无法在 jmf 中定位设备。.so 在引用材料的代码中直接提到。但不起作用！我正在为此使用 net beans，并且 jmf 库也包含在 netbeans 中。请帮我解决这个问题。我的代码：

package VideoSource;

/**
 *
 * @author sri 
 */
import java.awt.Frame; 
import javax.imageio.ImageIO;
import java.awt.Image; 
import java.awt.image.BufferedImage; 
import java.awt.image.RenderedImage;
import java.io.File;
import java.io.IOException;
import javax.media.Buffer; 
import javax.media.Manager; 
import javax.media.NoPlayerException;
import javax.media.Player; 
import javax.media.CaptureDeviceInfo;
import javax.media.control.FrameGrabbingControl; 
import javax.media.format.VideoFormat; 
import javax.media.util.BufferToImage; 
import javax.media.*;

public class frames {
     public static final String DEVICE ="vfw:Microsoft WDM Image Capture (Win32):0";

   //protected Player player;
    public static void main(String args[]) throws IOException, CannotRealizeException{
   try{ 

       CaptureDeviceInfo cdi = CaptureDeviceManager.getDevice(DEVICE);

    Player player = Manager.createRealizedPlayer(cdi.getLocator());
    player.start();
    FrameGrabbingControl frameGrabber = (FrameGrabbingControl) player.getControl("javax.media.control.FrameGrabbingControl");

   Buffer buf = frameGrabber.grabFrame();
   //BufferedImage buf1 = frameGrabber.grabFrame();
   // Convert frame to an buffered image so it can be processed and saved
Image img = (new BufferToImage((VideoFormat) buf.getFormat()).createImage(buf));
if(img!=null){
RenderedImage img1=(RenderedImage) img;
int i=0;
      File outputfile = new File("d:/Project/frame"+(i++)+".jpg");
      ImageIO.write(img1, "jpg", outputfile);
}
else
    System.out.println("null from frame grabbing");
//return img;
   }
   catch(NoPlayerException n)
   {

   }




}
}

我有例外：

Exception in thread "main" java.lang.NullPointerException
    at VideoSource.frames.main(frames.java:37)
Java Result: 1
4

0 回答 0